In recent years, interest in a secondary battery has rapidly increased due to reasons such as an economic advantage and an environmental advantage. The secondary battery is a device that stores external electric energy in a form of chemical energy and thereafter, generates electricity as necessary and a utilization range thereof has been extended to an electric vehicle in recent years. The secondary battery is constituted by at least one battery cell and may be used by extending voltage or a current amount by electrically connecting a plurality of battery cells according to a usage environment and a usage purpose thereof. In this case, when the plurality of battery cells that is electrically connected needs to be solidly supported, the plurality of battery cells may maintain an electrical connection state.
As such, a technology in which the plurality of battery cells is electrically connected and the plurality of battery cells is solidly supported has been already disclosed in Korean Patent Publication No. 2012-0051237 entitled “Battery Module Case”. The registered patent includes a case which is separated into upper, lower, and side surfaces and the plurality of battery cells is stably supported by the case.
However, when a separate case for supporting the plurality of battery cells is configured like the registered patent, there are problems described below.
First, as the number of battery cells joined to the inside of the case is limited, extension of the battery cell is limited.
Second, a weight, an appearance, and the like of the entire battery module constituted by the plurality of battery cells become large more than desired.
Third, manufacturing cost of the battery module is increased.